Business enterprises and autonomous bodies retain large volumes of data such as those of operational logs and sensor data, and there are needs for extracting useful information from such large volume data. The development in the information technology has been increasing the volume of collected hierarchical data, e.g., Extensible Markup Language (XML) data. Thus, there are demands for a technique to perform at high speed a complex data analysis on a large volume of data having a hierarchical structure, and for a user interface technique used with such an analysis technique.
JP-A-2003-162545 discloses a technique to store information such as data start position in an index file in order to enable a fast data search and extract in/from a Comma Separated Values (CSV) file where data is stored in a tree structure.
JP-A-2002-197099 and JP-A-2001-22766 disclose techniques where data are retained in a way specialized for cross tabulation in order to enhance the speed of cross tabulations at desired levels.
JP-A-2001-43237 discloses a technique where each attribute value has an index representing its position in a file so as to enable fast search of a record having a specified value at a specified field.
JP-A-Hei 11 (1999)-154155 and JP-A-2001-22617 disclose a technique where data are stored in a file such that data of a same field are stored continuously in order to enhance the speed of a processing involving only a specific field.
JP-A-2006-053724 discloses a technique to search an XML document using a schema mapping specification between an XML document and a relational table.
JP-A-2005-085166 discloses a graphics display system and a method for effectively presenting information obtained by data mining.
JP-A-2001-134575 discloses a system that detects a frequently appearing pattern in a database including a set of tree-structured data, by using a candidate pattern as an object of an aggregate calculation.